Description of Liquid Nitrogen Experimental Test Facility

The Liquid Nitrogen Test Facility is a unique test facility for ground-based liquid nitrogen experimentation. The test rig consists of an insulated tank of approximately 12.5 cubic ft in volume, which is supplied with liquid nitrogen from a 300 gal dewar via a vacuum jacketed piping system. The test tank is fitted with pressure and temperature measuring instrumentation, and with two view ports which allow visual observation of test conditions. To demonstrate the capabilities of the facility, the initial test program is briefly described. The objective of the test program is to measure the condensation rate by injecting liquid nitrogen as a subcooled spray into the ullage of a tank 50 percent full of liquid nitrogen at saturated conditions. The condensation rate of the nitrogen vapor on the subcooled spray can be analytically modeled, and results validated and corrected by experimentally measuring the vapor condensation on liquid sprays

Acquisition and correlation of cryogenic nitrogen mass flow data through a multiple orifice Joule-Thomson device

Liquid nitrogen mass flow rate, pressure drop, and temperature drop data were obtained for a series of multiple orifice Joule-Thomson devices, known as Visco Jets, over a wide range of flow resistance. The test rig used to acquire the data was designed to minimize heat transfer so that fluid expansion through the Visco Jets would be isenthalpic. The data include a range of fluid inlet pressures from 30 to 60 psia, fluid inlet temperatures from 118 to 164 R, outlet pressures from 2.8 to 55.8 psia, outlet temperatures from 117 to 162 R and flow rate from 0.04 to 4.0 lbm/hr of nitrogen. A flow rate equation supplied by the manufacturer was found to accurately predict single-phase (noncavitating) liquid nitrogen flow through the Visco Jets. For cavitating flow, the manufacturer's equation was found to be inaccurate. Greatly improved results were achieved with a modified version of the single-phase equation. The modification consists of a multiplication factor to the manufacturer's equation equal to one minus the downstream quality on an isenthalpic expansion of the fluid across the Visco Jet. For a range of flow resistances represented by Visco Jet Lohm ratings between 17,600 and 80,000, 100 percent of the single-phase data and 85 percent of the two-phase data fall within + or - 10 percent of predicted values

The Community Satisfaction with Village Infrastructure Development in Pinrang Regency, South Sulawesi, Indonesia

This study aims to: (1) determine the level of community satisfaction with infrastructure development in Patong village, (2) Determine the relationship between community satisfaction and infrastructure development in Patong village. A sampling technique is a targeted sample, that is, the selection of an informant who is deemed to be aware of the problem and who is believed to be able to be used as a legitimate data source. The number of samples in this survey was 29 inhabitants spread over the villages of Tante, Labulang, and Patong Village. Data collection is carried out using questionnaires and documentation. Data analysis is performed by descriptive statistical analysis, classic tool testing, and hypothetical tests. The results of the community satisfaction survey in Patong village, Pinrang Regency, which is community satisfaction in services is good (43.7%), and community satisfaction with infrastructure is quite good (51.2%). Therefore, services in Patong village need to be improved to achieve a smooth and effective administrative process. The results of this study also show that the correlation between community satisfaction and infrastructure development by a factor of r 0.460 means that between the variables of community satisfaction and infrastructure development in Patong village, Pinrang Regency, lies in the range of 0.400–0.599 table correlation coefficients, including the middle category. The value of the interest is 0.012, which is less than 0.05, which means that the variable for community satisfaction has a significant impact on the development of the infrastructure in Patong village, Pinrang Regency; therefore, cooperation with different countries is necessary so that the development of the infrastructure is in line with the needs of the community and the construction built by the Patong village administration, Pinrang Regency, offers a level of pleasure, comfort, safety, beauty and can be described when the structure of the building has a positive effect, which is directly felt by society. Keywords: community satisfaction, infrastructure development, village administratio

Characteristics of Residual Mixing Noise From Internal Fan/Core Mixers

The jet mixing noise from two fan/core mixer nozzles is studied. Acoustic data from two fan/core mixer nozzles are analyzed to determine the properties of the noise signatures. It was assumed that there were three major contributors to the total noise signature: noise from mixing of the fan and core streams internal to the nozzle; noise from residual mixing of the fan and core streams external to the nozzle; and the noise associated with the fully mixed jet. In general, the low frequency portion of the noise spectra can be associated with the fully mixed jet and can be predicted using an empirical correlation for single round nozzle jet noise. The properties of the noise in excess of the fully mixed levels are studied

Magnetic nanoformulation of azidothymidine 5’-triphosphate for targeted delivery across the blood–brain barrier

Despite significant advances in highly active antiretroviral therapy (HAART), the prevalence of neuroAIDS remains high. This is mainly attributed to inability of antiretroviral therapy (ART) to cross the blood–brain barrier (BBB), thus resulting in insufficient drug concentration within the brain. Therefore, development of an active drug targeting system is an attractive strategy to increase the efficacy and delivery of ART to the brain. We report herein development of magnetic azidothymidine 5′-triphosphate (AZTTP) liposomal nanoformulation and its ability to transmigrate across an in vitro BBB model by application of an external magnetic field. We hypothesize that this magnetically guided nanoformulation can transverse the BBB by direct transport or via monocyte-mediated transport. Magnetic AZTTP liposomes were prepared using a mixture of phosphatidyl choline and cholesterol. The average size of prepared liposomes was about 150 nm with maximum drug and magnetite loading efficiency of 54.5% and 45.3%, respectively. Further, magnetic AZTTP liposomes were checked for transmigration across an in vitro BBB model using direct or monocyte-mediated transport by application of an external magnetic field. The results show that apparent permeability of magnetic AZTTP liposomes was 3-fold higher than free AZTTP. Also, the magnetic AZTTP liposomes were efficiently taken up by monocytes and these magnetic monocytes showed enhanced transendothelial migration compared to normal/non-magnetic monocytes in presence of an external magnetic field. Thus, we anticipate that the developed magnetic nanoformulation can be used for targeting active nucleotide analog reverse transcriptase inhibitors to the brain by application of an external magnetic force and thereby eliminate the brain HIV reservoir and help to treat neuroAIDS

Acoustics and Thrust of Separate Flow Exhaust Nozzles With Mixing Devices Investigated for High Bypass Ratio Engines

Typical installed separate-flow exhaust nozzle system. The jet noise from modern turbofan engines is a major contributor to the overall noise from commercial aircraft. Many of these engines use separate nozzles for exhausting core and fan streams. As a part of NASA s Advanced Subsonic Technology (AST) program, the NASA Glenn Research Center at Lewis Field led an experimental investigation using model-scale nozzles in Glenn s Aero-Acoustic Propulsion Laboratory. The goal of the investigation was to develop technology for reducing the jet noise by 3 EPNdB. Teams of engineers from Glenn, the NASA Langley Research Center, Pratt & Whitney, United Technologies Research Corporation, the Boeing Company, GE Aircraft Engines, Allison Engine Company, and Aero Systems Engineering contributed to the planning and implementation of the test

Advanced Development Projects for Constellation From The Next Generation Launch Technology Program Elements

When United States President George W. Bush announced the Vision for Space Exploration in January 2004, twelve propulsion and launch system projects were being pursued in the Next Generation Launch Technology (NGLT) Program. These projects underwent a review for near-term relevance to the Vision. Subsequently, five projects were chosen as advanced development projects by NASA s Exploration Systems Mission Directorate (ESMD). These five projects were Auxiliary Propulsion, Integrated Powerhead Demonstrator, Propulsion Technology and Integration, Vehicle Subsystems, and Constellation University Institutes. Recently, an NGLT effort in Vehicle Structures was identified as a gap technology that was executed via the Advanced Development Projects Office within ESMD. For all of these advanced development projects, there is an emphasis on producing specific, near-term technical deliverables related to space transportation that constitute a subset of the promised NGLT capabilities. The purpose of this paper is to provide a brief description of the relevancy review process and provide a status of the aforementioned projects. For each project, the background, objectives, significant technical accomplishments, and future plans will be discussed. In contrast to many of the current ESMD activities, these areas are providing hardware and testing to further develop relevant technologies in support of the Vision for Space Exploration

Laser doppler velocimeter system for subsonic jet mixer nozzle testing at the NASA Lewis Aeroacoustic Propulsion Lab

A laser Doppler velocimeter (LDV) system developed for the Aeroacoustic Propulsion Laboratory (APL) at the NASA Lewis Research Center is described. This system was developed to acquire detailed flow field data which could be used to quantify the effectiveness of internal exhaust gas mixers (IEGM's) and to verify and calibrate computational codes. The LDV was used as an orthogonal, three component system to measure the flow field downstream of the exit of a series of IEGM's and a reference axisymmetric splitter configuration. The LDV system was also used as a one component system to measure the internal axial flow within the nozzle tailpipe downstream of the mixers. These IEGM's were designed for low-bypass ratio turbofan engines. The data were obtained at a simulated low flight speed, high-power operating condition. The optical, seeding, and data acquisition systems of the LDV are described in detail. Sample flow field measurements are provided to illustrate the capabilities of the system at the time of this test, which represented the first use of LDV at the APL. A discussion of planned improvements to the LDV is also included